Abby
pd. 4
10/4/11
West Branch River Study
Statement of the Problem:
What is the water quality of the West Branch of the Susquehanna River through
Curwensville?
Research:
The land around the sampling site is between farmland and a city. Farmland water
quality is usually good, and city water quality is usually poor. There is a bridge near the
sampling site as well as a road. There are plenty of trees in the area. There are no large
factories or industries near the site.
Hypothesis:
The water quality of the West Branch of the Susquehanna River across from the VFW in
Curwensville, PA is good, but not excellent, based on the land use.
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The independent variable is the water quality.
The dependent variable is the land use around the sampling site.
Materials:
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Shoulder length gloves
Waders
Hand lenses
Tweezers and spoons
Large, shallow dish pans
Plastic sorting tubs or ice cube trays
Taxonomic key to macroinvertebrate life
Calculator
Kick net
Abby
pd. 4
10/4/11
Procedure:
1. Find the sampling site. There should be three different sites all in a 91 meter (or
about 100 yard) area. The sites should be 41 meters (or about 45 yards) from any
man-made objects. It is better if the site has riffles.
2. Start at the most downstream site so that the other sites are not biased by
dislodging sediment or macro invertebrates. Select a one square meter riffle area.
3. Go upstream from the net holder about one meter and kick the first few inches of
the streambed up for about one minute. The net holder should hold the net at a 45
degree angle to the water’s surface and firmly against the streambed.
4. The kicker grabs the bottom of the net and removes it with a forward scooping
motion so that no macro invertebrates are carried away by the current when the net
is removed. The net holder and the kicker carry the net to shore.
5. Sorters use spoons and tweezers to remove macro invertebrates from the net and
sort them into containers to identify them. The macro invertebrates need to be
sorted because some of them would harm others if they were in the same container.
6. Repeat the above steps at the other two sites.
7. Identify and record the types of macro invertebrates collected.
8. Gently release organisms upstream from where they were collected.
Results:
Macro Invertebrates found in West Branch of
Susquehanna
60
Number found
50
40
30
20
10
0
Dobsonfly Larva
Caddisfly Larva
Other Mayfly
Type of Macroinvertebrate
Fingernail Clam
Abby
pd. 4
Type of Macro Invertebrate
Dobsonfly Larva
Caddisfly Larva
Cranefly Larva
Fingernail Clam
Number found
8
51
20
6
Taxa
1
1
1
2
10/4/11
Relative Aubndance
Rare
Common
Common
Rare
The location where the data was collected was in the West Branch of the Susquehanna
River across from the VFW in Curwensville. The date was 9/26/11 and the time was
11:30 a.m. There were 19 participants in the experiment. The weather was mostly
cloudy and the temperature was 26 degrees Celsius (79 degrees Fahrenheit). The water
temperature was 19 degrees Celsius (66 degrees Fahrenheit) and the pH of the water
was 6.
Analysis:
In the Group 1 Taxa there were 8 Dobsonflies collected, making them rare, 51 Caddisfly
Larvae, making the common, and 20 other Mayflies, making them common. In the
Group 2 Taxa there were 6 Fingernail Clams collected, making them rare. There were no
organisms collected from the Group 3 Taxa.
Most of the organisms collected were from the Group 1 Taxa, meaning they were the
most sensitive. A wide array of organisms was not found; only a few types of organisms
were found.
Conclusion:
The water quality is poor, but just barely. The water quality rating for the West Branch
of the Susquehanna across from the VFW in Curwensville is 19.4, and the cutoff to be
fair water quality is 20. So the water quality is on the upper end of poor.
My hypothesis was wrong. I predicted that the water quality would be good, but it was
poor. Therefore, the conclusion rejects my hypothesis. To improve my experiment, I
could have tried to collect macro invertebrates on different days when the weather,
water temperature, air temperature, etc. was different.
Abby
pd. 4
10/4/11
Through this experiment, I learned that you cannot base your hypothesis on just one
factor. My hypothesis was based only on the land use, but the weather, temperatures,
pH, time of day, and time of year might also have an effect on the water quality.
Self Evaluation: 100/100